The Last Days of the Mighty Mekong, by Brian Eyler, director of the Southeast Asia program at the Stimson Center, takes the reader on a journey from glaciers in China to rice fields in Vietnam, stopping along the way in Cambodia, Laos, and Thailand. The book describes how unsustainable human society’s current relationship is with the Mekong, which he defines not just as a river but as a complex ecological system that includes glaciers, lakes, deltas, and other smaller rivers in the region. The Mekong is important globally in terms of biodiversity—thirteen times more fish are caught annually from the Mekong than from all of North America’s lakes and rivers combined. It is also important strategically—the Mekong starts in China and flows through mainland Southeast Asia, an economically dynamic region where Beijing is increasingly the dominant external power. The Mekong has become increasingly important to trade as well, as the river has been made more navigable (controversially) through efforts by China to dredge rapids and remove rocks, among other strategies.